did not try before but found now in CB 2.0.1 and J3.3.4 and php5.4:
I created a new user in backend for a friend (with an automatic created password). He said, that he cannot login.
Then I tried to create a new user for me with an automatic created password). And tried to login. I didn't succeed.
I had to click on forgot login and to ask for a new password. After that, I had no problems to login.
It's rarely that I create a user for me. So I found this problem accidentally.
Can someone reproduce this?
It seems only to be, when creating new user from backend!
EDIT:
strange, I made it a second time, now login worked.